Staggered convergent biplane



A. A. MERRILL.

STAGGERED coNvERGENT BIPLANE.

APPLICATION FILED MAY 3l, 1916.. 1,355,990. Patented Oct. 19, 1920.

2 SHEETS-SHEET l.

A. A. MERRILL.

STAGGERED CONVERGENT BIPLANE.

APPLICATION FILED MAY 3I, 191s.

1,355,990. y 'Patented o@f'.19,1920. f@ im ff 55 *W T1@ if', f) 5` L; if? E6 L?? 75 UNITED kSTATES PATENT ori-fics.

ALBERT A. MERRILL, F LOS ANGELES, CALIFORNIA.

STAGGERED CONVERGEN T BIPLANE.

, Specication of Letters Patent.

Patented Oct. 19, 1920.

f Application mea my a1, 191s. serial N'o. 100,954.

. specification.

This invention relatesto aeroplanes, and the general object of this invention is to provide a machine more nearly inherently sta` ble than machines heretofore constructed, and to provide a machine in which vertlcal control may be and is effected wlthout the use of an elevator.

I can best explain the general nature of my invention by referring first to the common mono-plane type of machine. Such a, machine in reality comprises twoplanes, a

large supporting plane and a small following plane at some distance behind the supporting plane at the rear end of the frame work. The elevator usually follows immediately behind this following plane. At ordinary speeds of flight the tlme elapsing between the entry ofthe forward supporting plane into disturbed air and the time when the following plane enters said air is suficent to allow the machine to oscillate about its lateral axis before the` instant when the following plane enters said air and when the balance of the forces is restored. Thefa'ct that such oscillations ofthe machine can and do take place under such circumstances makes it necessary to use an elevator to overcome or counterbalance the turning moment of oscillation as quickly as possible. And, even with the best constructed machines, accidents are liable to occur due to the comparatively large time period between the instant when the supporting plane enters the disturbed air and the instant when the following plane enters said air.

I reduce this time neglible quantity by pla-ne 'closely behind period to apractically placing the following the supporting plane;

-that is, generally speaking, by decreasing the horizontal distance between the two planes. The reducing of this distance of -course makes is necessary to increase the size of the following plane in order that that plane may still have the same righting moment as before about the center of gravity of the machine. I make the horizontal distance between the planes so small that,

under all ordinary circumstances, and at any of the usual speeds of flight, the time element above referred to is so short that the inertia of the machine about its lateral axis cannot -be overcome in that time period by any ordinarily encountered force, suf-r iciently to sensibly rotate the whole machine about the lateral axis. the case, the necessity of the elevator is done away with; and I provide means for guiding the machine vertically by making arelative longitudinal shift between the center' of gravity and center of support. I preferably make this shift by shifting the center of gravity. I shift the -center of gravity by the expedient of shifting a weight longitudinally in the machine; and thls weight may be the whole power plant and the pilot, or any other weight.

y invention will be best understood fiom the following specification taken with reference to the drawings, in which speciiication and drawings'I illustrate a preferred form of machine embodying my said invention. In these drawings Figure 1 is a side elevation of a machine embodying my invention. Fig. 2 is a plan of the same, parts being broken away for purposes of illustration, Fig is a front elevation taken as indicated by line 3 3 on Fig. 1, Fig. 4 is an enlarged detail section taken as indicatedl by line 4-4= on Fig. 3, Fig.`5 is a further enlarged detail section taken as indicated by line 5-5 on Fig. 4, and Fig. 6

This being 1s a diagram illustrating certain principles of n1 invention.

I s all refer first particularly to Fig. 6. Therein I show a forward supporting plane 10 and a following pla-ne 11 arranged aft and preferably beneath the supporting plane; and I show at 12the usual position of the following plane on a monoplane. The distance denoted L is approximately the leverage distance between the plane 12 and the center of gravity of the machine, while the distance denoted L is approximately the leverage. Idistance between the plane 11 and the center of gravity. In the diagram it will `be noted that the' plane 11 (the plane of least inclination) is placed behind the plane 10 by a distance equal to about one half of the width of the plane 10. The righting moment of the plane 12 about the center of gravity o f a mono-plane is measured by the product of the` force exerted upon the plane 12 and its 'distance L from 10; but is placed at a slighter angle of in! clination than that of the plane 10. For in` stance, in a typical construction, I place the planes 1'0 and 11 in the relative positions shown, placing the chord of the plane 10 at an inclination of about seven degrees and the chord of the plane 11 at an inclination of about four degrees, the two planes having a rearward convergence of about three degrees. It should be noted that the essential feature of this disposition is that one surface is placed behind the other, and that the rear surface has the lesser inclination; but it is immaterial whether the rear surface is below or above the front surface. `When the rear surface is above the convergence is forward. In either case the moment of the righting couple is the same. The horizontal distance between the planes 10 and 11 is approximately half the width of the'planes, or with a chord of 6 feet this distance is 8 feet; and the time element hereinbefore referred to corresponding .to this linear distance of 3 feet, and for a speed of say 60 miles per hour, is 1/29th of a second. This time element is too small to allow of any oscillation of the whole machine about its lateral axis.

I nowrefer particularly to Figs. l to 5. I show the two planes 10 and 11 placed in the relative positions hereinbefore explained, the planes being framed with struts 13 and brace wires 14 in the usual manner. The machine is'provided with any suitable start-i ing and landing apparatus suoli as is shown at 16; and a rearwardly extending frame Work 17 is provided for carrying the vertical rudder 18 for steering. `rllhe planes '10 and 11 are provided at each end of the rear edge with the ailerons 20 and 21. rllhe ailerons at each end are connected by struts 22, whose connection to the ailerons may be pivotal in any of the well known manners, and all of the ailerons are made to act co4 operatively by a suitable connecting means, preferably a connecting wire 23 which connects to each of the upper ailerons and passes downwardly and over pulleys 19 and across the bottom part of the machine. Control of the ailerons is preferably by means of a wheel 24 located in front pilot seat 25. Wires 26 wind around a drum or spool 27 operated by the wheel 24, and these wires 26 extend outwardly and upwardl and over pulleys 28 beneath the upper p ane 10 and thence downwardly to connect with the The motor 40, with the propeller 41, andcontrols 24 and 31, and pilotseat 25 are all mounted upon a sliding base. This sliding base 45 is mounted in suitable ways 46 between suitably constructed beams 47; the

beams and ways being so placed that the sliding base is arran ed parallel to the longitudinal axis of te -whole machine. I have hereinbefore stated that in order to shift the center of gravity of the machine I prefer to shift the weight longitudinally; and in the form of mechanism herein described the weight to be shifted includes the power plant, the controls and the pilot, all of which are carried on the sliding base 45. In the normal position of the sliding base and the parts carried thereon, the center of gravity of the whole machine' is at such a point that the machine will fly at a predetermined angle of incidence; and provision is made for moving the sliding base and the parts carried thereon either forward or back of the normal medial ,position so as to materially shift the center of gravity either forwardly or rearwardly. Shifting the center of gravity with reference to the center of support immediately changes the angle of incidence and causes the machine to climb or glide, as may be desired.

I prefer to move the sliding base longitudinally by means of a hand lever 50 mounted upon a transverse shaft 51, extending across the sliding base 45 and carrying near its center a drum 52. A cable 53 winds around the drum in the manner indicated and the ends of the cable are secured to the cross pieces 54' which connect to and space the beams 47. A toothed sector 55 is provided for the lever 50, and a dog 56, e'ntering the sector notches, holds the lever in any set position; and consequently holds the sliding base 45 in any .set position with reference to the ways 47 and 46.

It will be understood that, by arranging the following plane closely behind the supporting plane, I provide that the machine shall not oscillateI about the lateral axis u on entering disturbed air conditions. onsequently the only vertical control neoessary is that needed for guiding the mitchine up and down; and, in the .specific preferredform described, this .is providedby shifting the center of gravity of the machine. -It will be noted that I place a considerable portion o'f the complete weight of the machine upon the-sliding base 45; so that a movement ofthe sliding base causes a relatively considerable movement of the center of gravity of the whole machine. In

such circumstances it is not necessary to move the sliding base a great distance either ahead or behind of its normal medial position for extreme control of the machine; and it will be noted that these movements do-not affect the control wires 26 and 30 as `those. control wires normally eXtend transversely outwardly to the outer ends of the lanes l0 and 11, and normally extend at rlght angles to the line of movement of the sliding base; so that a very slight resilient extension of the wires is sufficient to allow the forward and back`1novement of the sliding base.

Having described a preferred form of my invention, I claim:

1. In a Hying machine, supporting surfaces embodying exclusively a plurality of supporting planesv spaced one above the other and slightly in front of the other, the chords of said surfaces being convergent, and the angle of incidence of the front surface being greater than that of the rear sur-y face, theV horizontal spacing of said planes being relatively small, and means for longitudinally shifting the center of gravity of the machine as a whole, said lastmentioned means being the sole vertical steering means.

2. In a fiying machine, supporting surfaces embodying exclusively a pluralityof supporting planesl spaced one above the other and one slightly in front of the other,

f setting said framea 3. In a iying machine, supporting surfaces embodying exclusively a plurality of supporting planes spaced one above the other and one in front of the other, the chords of said surfaces being convergent and the angle of incidence of the front surface being greater than that of the rear surfaces, the horizontal spacing of saidplanes being relatively small, and a single means for Lvertically steering the machine, said means operating by longitudinally shifting the position of the center of gravity of the machine as a whole, and embodyin a weight and means for shifting said weight longitudinally of the machine.

4. In a flying machine, supporting surfaces embodying exclusively a plurality of supporting planes spaced one above the other and one in front of the other, the chords of said surfaces being convergent and the angle of incidence of the front surface being greater than that of the rear surface, the horizontal spacingof said planes being relatively small, and ya single means for vertically steering the machine, said means operating by longitudinally shifting the osition of the center of gravity of the mac ine as a whole, and embodying a lonl.gitudinally movable frame mounted upon the machine, power plane and propulsion means mounted upon said longitudinally movable frame, controls mounted upon said lon 'tudinally movable frame, and meansunelrcontrol of the pilottfor moving and `Inwitness that I claimfthe foregoing I l have hereunto subscribed my name this 23d 80 day of' May, `1916.,

narrar A. MERRILL. Witnesses:

JAMES T. BARKELEW,

EDWARD H, Bannnnnw. 

